1. Field of the Invention
The present invention relates to a sewing machine having a plurality of needles and being provided with a threading the device for threading the plurality of needles thereof.
2. Description of the Related Art
A conventional lock stitch sewing machine is provided with a needle bar holding a plurality of needles. Typically, a pincette has been used in manually threading the needles of such a lock stitch sewing machine. A method of manually threading needles using a threading attachment is disclosed in Japanese Utility Model Publication No. Sho 53-35061.
However, a threading operation using a pincette or a threading attachment is often obstructed by a looper and an edge trimmer disposed in front of the needles, which makes threading difficult.
On the other hand, a sewing machine having a needle bar holding a single needle is provided with a threading hook supported for turning in a vertical plane so as to be advanced into and retracted from the eye of the needle. When the threading hook is advanced into the eye of the needle, the needle thread is hooked by the threading hook and is passed through the eye of the needle when the threading hook is retracted. Since the threading hook only needs to be turned for threading the needle, the threading hook facilitates threading. Hence, a threading operation using the threading hook is easier than a threading operation using a pincette or a threading attachment.
Accordingly, it has been desired to provide a lock stitch sewing machine having a needle bar holding a plurality of needles with a threading hook to facilitate threading the plurality of needles.